重力钝感的水稻突变体在重力和微重力条件下淀粉体的观察分析

植物向重性的研究一直受到关注,主要的研究集中在双子叶模式生物拟南芥中,而对单子叶植物的研究却很少。植物对重力感受的方式存在多种解释,但目前大量证据表明淀粉体—平衡石理论较为合理,它认为淀粉体作为平衡石在植物向重性反应中发挥了重要的作用。经过100多年的研究,现已从生理学与遗传学的角度证实了含有淀粉体的根冠中柱细胞和茎的内皮层细胞是植物重力感受的部位,淀粉体作为重力感受器被越来越多的实验证据证明。地球上重力无处不在,要研究微重力对植物体极性生长的影响只能借助于能模拟失重环境的回转器。近年来,人们对植物向重性机制的了解主要来自缺失或缺少

OBSERVATION AMYLOPLASTS IN THE GRAVITY-INSENSITIVE MUTANT OF RICE UNDER GRAVITY AND MICROGRAVITY CONDITIONS

Using histochemistry and optical microscope, we examined the number and the size of amyloplasts in specializd tissues of gravitropically receptive organs-tissues such as the coleoptile and sheath of rice mutant (insensitive to gravity) and wide type (Oryza sativa L. subsp. japonica) (Zhonghua 11). We found there was no statistical difference between the mutant and wide type, both of which grew on earth or on the clinostat respectively. On earth, it was found that amyloplasts sedi-mented at the distal end of each cell of the special starch sheath tissues and re-sedimentation of amyloplasts toward the direction of gravity was almost completed in 5 minutes after inverting the seedlings. On the clinostat, amyloplasts dispersed in the starch sheath tissue. Such observations indicated that the mutation was not resulted from the starch-deficiency or starch-absence, the further research is going on.